The present invention relates to insulation inspection apparatus for inspecting the insulation of a motor.
Since a motor has a structure in which a brush is in contact with a commutator, the brush is worn, and abrasion powder is scattered. Because of the abrasion powder, the insulation between a motor case or another metal part and the electric system of the motor is subject to be deteriorated. In addition, dust may enter into the motor by using the motor for a long period of time, and the insulation may be deteriorated.
The deterioration of insulation may occur regardless of the types of motors such as a DC motor and an AC motor to cause an accident of stopping the motor or a leakage accident. For this reason, the insulation of the motor must be periodically or appropriately inspected.
As a conventional insulation inspection method, a method called a so-called mega test and the like is used. For example, a high voltage, which does not break a motor, is applied between the power lines and the ground of the motor, and a resistance at this time is measured to perform the test.
However, in the method in which a power voltage is applied to a motor, in order to prevent the high voltage from flowing into the control device of the motor, the motor and the control device must be completely separated from each other. For this reason, in a conventional insulation inspection, a disconnection operation of a signal line and a connection operation upon completion of the inspection must be performed each time for inspecting the insulation, and very long time is disadvantageously required to perform the insulation inspection.
It is an object of the present invention to provide an insulation inspection apparatus, which can perform insulation inspection for a motor within a short period of time without separating the motor and a control device from each other.
According to a technical aspect of the present invention, an apparatus for inspecting the insulation of a motor includes a charged body which is electrically insulated from a motor electrical wire for supplying a power to the motor and arranged near the motor electrical wire, and a voltage measurement unit which measures an electromotive force induced in the motor electrical wire by the charged body.
According to another technical aspect of the present invention, an apparatus for inspecting the insulation of a motor includes a conductor which is electrically connected to a motor electrical wire for supplying a power to the motor, a charged body which is electrically insulated from the motor electrical wire and the conductor and which is arranged near the conductor, and a voltage measurement device which measures an electromotive force induced in the conductor by the charged body.
According to still another technical aspect of the present invention, a method of inspecting the insulation of a motor includes the step of electrically insulating a charged body arranged near a motor electrical wire from the motor electrical wire for supplying a power to the motor, and the step of measuring an electromotive force induced in the motor electrical wire by the charged body.